Table 1.

Sociodemographic Characteristics in the NSSI Group (n = 225) and Controls (n = 225)

Sociodemographic Characteristics		NSSI (n, %)	Controls (n, %)	t/U	P
Gender				24,750.00	0.567
Male		47 (20.89%)	51 (22.67%)
Female		178 (79.11%)	174 (77.33%)
Age	Mean ± S.D.	15.13 ±1.92	15.05 ±1.78	0.43	0.665
	Range	11–19	12–19
Education level				23,962.50	0.243
Primary school		135 (60.00%)	147 (65.33%)
Junior high school		90 (40.00%)	78 (34.77%)
Family structure				23,877.00	0.266
Big family (parents, children and grandparents together)		62 (27.56%)	53 (23.55%)
Nuclear family (parents and children)		120 (53.33%)	157 (69.78%)
Single- parents family		27 (12.00%)	8 (3.56%)
Children “Left-behind”		13 (5.78%)	6 (2.67%)
Others		3 (1.33%)	1 (0.44%)

Abbreviation: NSSI, non-suicidal self-injury.